Risks of interrupting drug treatment before surgery

A cross-sectional study of preoperative medication adherence and early postoperative recovery

STUDY OBJECTIVE

To quantify the impact of preoperative medication adherence on recovery length of stays and complication rates.

DESIGN

Cross-sectional analytical study.

SETTING

Postanesthetic care unit (PACU) of a single-center tertiary hospital.

PATIENTS

Surgical patients admitted for surgery at our institution over a 4-month period.

INTERVENTION

A data collection tool was used to collect demographic data, length of stay in recovery, prespecified conditions likely to impact on PACU recovery (chronic pain, insulin-dependent diabetes, epilepsy, hypertension, on a methadone program, and Parkinson disease), medication compliance, and complications in PACU.

MEASUREMENTS

Differences among categorical variables were assessed for significance using the χ² test; continuous parametric data were compared using a time to survival analysis via Kaplan-Meier estimates and Cox proportional hazard regressions to account for possible confounders.

MAIN RESULTS

Preoperative medication compliance for the prespecified conditions was 65.1%. Patients with a preoperative condition spent more time in the PACU compared to patients without a preoperative condition. Time in PACU was not significantly longer for patients who took their medications compared to those who failed to take their medications. Patients with multiple prespecified conditions were more likely to incur a postoperative complication compared to patients without a prespecified condition. Patients with preoperative hypertension and insulin-dependent diabetes incurred higher complication rates in PACU for medication nonadherence compared to medication adherence.

CONCLUSION

This study taken together with accruing evidence suggests that preoperative medication omission remains an ongoing issue that can influence complication rates in the PACU. Patients with preoperative conditions stay longer in PACU, and medication omission was associated with higher rates of certain postoperative complications in PACU. This identifies patients likely to require more interventions and greater recovery resources. Further research into the impact of medication omission on recovery parameters after discharge from the PACU is warranted.

Interférence des médicaments cardiovasculaires avec l'anesthésie et la chirurgie

Decisions about chronic treatments during the perioperative period must be made at the presurgical anesthesia consultation. It is increasingly rare to stop treatment during this period, because: This new rule is applied particularly to patients with cardiovascular disorders. Beta blockers have a special role in preventing the onset of postoperative cardiovascular events. The role of statins requires further precision but they appear to fit into the same preventive approach. Interruption of antiplatelet agents appears to be associated with a risk of arterial thrombosis in patients with coronary conditions, notably those with conventional stents and most especially those with drug-eluting stents.

Drug absorption from the small intestine in immediate postoperative patients

BACKGROUND

The effects of surgery on gastric emptying have been documented for a considerable time, but less is known about the effects in the small intestine. It is thought that there is minimal diminution in the absorptive capacity of the small intestine after operation, although there is no literature on drug absorption in the early period after surgery. This study investigated drug absorption from the small bowel in patients undergoing abdominal surgery.

METHODS

A prospective study of patients undergoing major abdominal surgery in which patients acted as their own preoperative controls was carried out. Patients were administered the test substances, acetaminophen and (99m)TcDTPA, before operation and 2 days after operation. Small intestine transit times, plasma concentrations and other pharmacokinetic variables were compared using Student's paired t-test. Two complementary studies were carried out to establish pharmacokinetic parameters.

RESULTS

There were no significant differences in the pre- and postoperative values of t(max), area under the curve, and area under the moment curve (AUMC) before and after operation (P>0.05). There were significant differences between the pre- and postoperative values of C(max) [C(max (preop))>C(max (postop)); P<0.05] and the pre- and postoperative values of mean residence time (MRT) [MRT((preop))<MRT((postop)); P<0.01].

CONCLUSIONS

Drug absorption from the small bowel in the postoperative patient does not differ significantly from its preoperative absorptive capacity.

Post-operative delirium after hip fracture treatment - a review of the current literature

Delirium is a common accompaniment of physical illness in old age, affecting approximately one out of five of those admitted to medical wards, the number being higher for elderly with fractured femurs. Although its existence has long been recognized its exact pathophysiology has not yet been fully elucidated. The present article presents up-to-date information concerning the etiology, pathophysiology, prevention and treatment of the post-operative delirium after hip-fracture treatment. The fact that its diagnosis remains mainly clinical requiring a high index of suspicion, both from nursing and medical staff, results in important under-recognition of the syndrome. Delirium is a medical emergency and if not promptly and urgently treated, or even better prevented, may have serious consequences for the patient and the family members. Proper measures for its prevention and treatment result in shorter hospital stay of the patients, less financial cost and better surgical outcome and rehabilitation of the elderly patient.

Pathogenesis of and management strategies for postoperative delirium after hip fracture: a review

BACKGROUND

Postoperative delirium is a frequent and serious complication in elderly patients following operation for hip fracture, leading to an increased risk of complications. The pathophysiological mechanisms are unresolved, but probably multifactorial. The purpose of this review is to summarize current knowledge about the pathogenesis of postoperative delirium with a view to finding strategies for prevention and management.

METHOD

We conducted an Internet search through the Medline database (1966-March 2003) and supplemented it with a manual search. We included 12 studies which specifically discussed pathogenic factors or interventions against postoperative delirium following operation for hip fracture.

RESULTS

1,823 patients were included with an average incidence of delirium of 35%. We concentrated on pre-, intra-, and postoperative risk factors. Only advanced age and dementia met our fixed criterion of "strong evidence" for a significant association. Hence, from the studies that we reviewed we were unable to find intraoperative or postoperative factors with "strong evidence" for a significant association with delirium.

INTERPRETATION

Postoperative delirium is a serious complication. The pathophysiology leading to delirium after hip fracture surgery still remains to be clarified and no single drug or surgical regimen has proven to be preventive. This calls for more detailed investigations of the differential role of different pathogenic mechanisms, as well as an aggressive multimodal approach to enhance recovery and reduce morbidity, as has proven to be successful in a variety of elective surgical procedures. Such multimodal interventional studies represent a major task for orthopedic departments in collaboration with anesthesiologists, geriatricians, physiotherapists and nursing staff.

Co-medications, pre-medication and common diseases in the elderly

Typically, old patients scheduled to undergo a surgical procedure take many medications for various disorders. The anaesthetist must consider the benefits and/or risks of continuation or withdrawal of such chronic medications. This chapter reviews these issues in respect of cardiovascular drugs (calcium channel blockers, beta adrenoreceptor antagonists, angiotensin-converting enzyme inhibitors and angiotensin receptor antagonists) and of psychotropic and antiparkinson medications and insulin. Focus is put on the few scientific studies available and on the recommendations given by experts in the field.

Interrupting drug therapy in the perioperative period

Millions of patients undergo surgery each year and an increasing proportion of these patients are consuming therapeutic drugs. Drug therapy is often withheld in the immediate perioperative period and after major surgery, in particular, there is often a prolonged period of fasting. This may lead to withdrawal effects including recurrence or worsening of patients' disease symptomatology. These effects will occur during a period of physiological and pathophysiological stresses and render patients more vulnerable to drug withdrawal phenomena. Thus, patients may be exposed to greater and sometimes unnecessary risks in the perioperative period. There are relatively few studies that have investigated this problem. The ones that have, however, confirm that drug abstinence in the perioperative period is a relatively common phenomenon and one study has demonstrated an association between duration of drug abstinence and adverse outcomes. The pathophysiological effects of major surgery on gastrointestinal function, neuro-humoral and cytokine adaptive responses to surgical stress are under-appreciated. These responses can reduce the effectiveness of oral administration and exacerbate co-existing disease processes. These problems are compounded by a fragmented approach to perioperative drug therapy with no one group of healthcare professionals assuming responsibility for this aspect of care. This may in part be a consequence of the complexities of rationalising drug therapy in the perioperative period together with the lack of readily available and evidence based information strategies for individual drugs or drug classes. An additional problem relates to the formulations, inherent pharmacokinetics and limited routes of administration of many prescribed drugs. These can prevent a 'seamless' transition from preoperative to postoperative management. Consumers, health professionals, pharmaceutical companies and drug regulatory agencies must all play a part in rectifying this problem. There remains a need for further research to clarify the effects of abstinence on patient outcomes and also to identify optimum strategies to avoid unwanted drug abstinence.

Multimodal strategies to improve surgical outcome

OBJECTIVE

To evaluate the effect of modifying perioperative care in noncardiac surgical patients on morbidity, mortality, and other outcome measures.

BACKGROUND

New approaches in pain control, introduction of techniques that reduce the perioperative stress response, and the more frequent use of minimal invasive surgical access have been introduced over the past decade. The impact of these interventions, either alone or in combination, on perioperative outcome was evaluated.

METHODS

We searched Medline for the period of 1980 to the present using the key terms fast track surgery, accelerated care programs, postoperative complications and preoperative patient preparation; and we examined and discussed the articles that were identified to include in this review. This information was supplemented with our own research on the mediators of the stress response in surgical patients, the use of epidural anesthesia in elective operations, and pilot studies of fast track surgical procedures using the multimodality approach.

RESULTS

The introduction of newer approaches to perioperative care has reduced both morbidity and mortality in surgical patients. In the future, most elective operations will become day surgical procedures or require only 1 to 2 days of postoperative hospitalization. Reorganization of the perioperative team (anesthesiologists, surgeons, nurses, and physical therapists) will be essential to achieve successful fast track surgical programs.

CONCLUSIONS

Understanding perioperative pathophysiology and implementation of care regimes to reduce the stress of an operation, will continue to accelerate rehabilitation associated with decreased hospitalization and increased satisfaction and safety after discharge. Developments and improvements of multimodal interventions within the context of "fast track" surgery programs represents the major challenge for the medical professionals working to achieve a "pain and risk free" perioperative course.